Chuck control circuit



May 28, 1963 R. E. BECKER 3,091,256

CHUCK CONTROL CIRCUIT May 28, 1963 R. E. BECKER CHUCK CONTROL CIRCUIT 2 Sheets-Sheet 2 Filed Sept. 6, 1960 6r Chl/M5 o f TCi WDW/w m .ffw rLW/.Ju il rl W IMD, @w

United States Patent 3,091,256 CHUCK CONTROL CIRCUT Robert E. Becker, Logansport, Ind., assignmto Logansport Machine Co., Inc., Logansport, Ind., a corporation of Indiana Filed Sept. 6, 1960, Ser. No. 53,985 Claims. (Cl. 137-622) This invention relates -to `a iluid pressure control circuit for operating a hydraulic chucking cylinder.

One purpose of this invention is to provide a huid pressure circuit of the type described which has a minimum of control lelements and which is effective to provide a high and a low pressure at one side of the chucking cylinder and a high pressure at the opposite side.

Another purpose `of this -invention is to provide a fluid pressure circuit of the type described which is effective to move a chucking cylinder between an operating position and a release position.

Another purpose is to provide a hydraulic circuit of the type described which has :three operating positions so that a work piece may be strongly gripped in a chuck, held at a reduced pressure in the chuck, and released from the chuck.

Another purpose is an improved method of operating a chucking cylinder through the use of a hydraulic circuit.

Other purposes will appear in the ensuing specification, drawings 'and claims.

The invention is illustrated diagrammatically in the following drawings wherein:

FIGURE 1 is a circuit diagram of the Huid pressure circuit disclosed herein,

FIGURE 2 is a section through one of the valves in the circuit showing the valve member in one position, and

FIGURE 3 is a section, similar to FIGURE 2, with the valve member in the opposite position.

Before describing the overall fluid pressure circuit and its operation, the valves A and B of the circuit will be described in detail. As valve A and valve B are identical, only one of these valves will be described. Like parts on valves A and B are designated by either (a) or (b) after the respective number.

Assuming that the valve of FIGURES 2 and 3 is valve A, the valve includes a valve housing a closed by cover plates 12a and 14a, which together deiine a valve chamber 11a. Mounted within the chamber 11a is a reciprocal valve member 16a having two spaced lands 18a and 26a. The valve member 16a may be reciprocated by `a control rod or shaft 22a which is operated by a handle or the like 24a pivoted on a ange 26a of cover plate 12a. FIG- URE 2 shows the valve in one position and FIGURE 3 shows the valve in the opposite position.

IFormed in one side of the valve housing 10a are three spaced ports 28a, 30a and 32a. Each of these ports open into an annular groove formed on the inside surface of the housing 16a, the grooves being designated respectively at 34a, 36a, and 38a. There are two additional annular grooves formed on the inside surface of housing 10a which are connected together by a passage 40a, these grooves being designated at 42a `and 44a. The passage 40a is connected to an exhaust port 46a.

Turning now to lFIGURE l, a source of pressure 50 may be connected by a suitable pipe or hose 52 to a high pressure regulator 54, which preferably reduces the pressure from the source to a satisfactory operating level, such as 60 p.s.i. A pressure gauge 56 may be connected in line 58 which connects the high pressure regulator 54 to port 30a of valve A. A line 60 is connected between port 28a of valve A and port 30h of valve B. Port 2gb on valve B is connected by a line 62 `to inlet port 64 in rotating distributor shaft housing 66.

A chucking cylinder 67 includes a piston 68 reciprocal in a chamber 70 and having a shaft 72 mounted thereon `which is connected to the chuck. Movement of piston 68 in one direction, for example to the left, is effective to move the chuck to a closed position wherein it grips the work piece, and movement to the right is eifective to release the work piece.

The chucking cylinder 67 and housing 66 include a passage 74 which connects the inlet port 64 with the right hand side 76 of the chamber 70 `and a further passage 78 which connects the left hand side Sti of the chamber 70 and a -second inlet port 82. A line S4 connects the inlet port 82 and port 32a on valve A.

A second pressure regulator valve 86 is connected by line 88 to the source of pressure 5t) and preferably is set at -a low pressure, for example 15 p.s.i. A pressure indicating dial 90 may be placed in line 92 which connects the pressure regulator 86 and an exhaust regulating valve 94. The exhaust valve 94 is preferably set to open at a pressure of approximately 20 p.s.i., for a purpose that will appear hereinafter. A line 96 connects the exhaust regulator 94 with exhaust port 46b of Valve B. An exhaust line 98 is connected to exhaust port 46a to complete the hydraulic circuit shown. Both the exhaust line 9S and the exhaust valve 94 lmay either be connected to a suitable storage tank, or may open to atmosphere.

The use, operation and function of the invention are as follows:

Shown and described herein is a fluid pressure circuit for operating a chucking cylinder and which is effective to both move the chuck into position to grip the Work piece and to release the work piece. In addition, the hydraulic circuit is effective to reduce the clamping pressure with which the chuck holds the work piece.

The operation will be illustrated in connection with hydraulic pressure, although the system may also be pneu-matically operated. When valves A and B are in the position shown in FIGURE l, high pressure hydraulic iluid will pass through the pressure lregulator 54, where the pressure is reduced to approximately 60 p.s.i., and then to valve A. It should be pointed out that the various pressures mentioned are for purposes of illustration only and may be varied. The pressure fluid will ow through port Sila into chamber 11a and out of port 28a through line 60 to port 30h of valve B. At valve B the pressure ilu-id will flow into chamber 11b, then out port 28h through line 62 to inlet port 64 on the housing 66. rllhe pressure uid will then pass through passage 74 to the right hand chamber 76 and so move piston 63 to the left, as shown in FIGURE l, so that the chuck is moved to the operating position and iirrnly grips the work piece. As piston 68 moves to the left, the pressure fluid in the left hand chamber 8G will be exhausted through passage 78, port 82 and line 84 to port 32a of valve A. Port 32a is in communication through chamber 11a with passage 44a and hence to exhaust port 46a. In other Words, the pressure fluid in the left hand chamber Si)y will be exhausted through valve A to line 98 and to either atmosphere or a suitable storage tank.

It is at times desirable to hold the Work piece in the chuck jaws at reduced pressure. For example, when iinishing rings or similar parts, it is customary to start with stock having a relatively heavy wall section. Such a part may be gripped tightly in the chuck for an initial rough cut. After the rough or heavy cut, the Wall thickness is reduced to a point Where the work piece should be gripped with less force in order to prevent distortion of the finished article. To reduce the pressure on the chuck, valve A remains in the position shown and the operator moves valve B to the position of FIGURE 3. As the valve member 16h moves to the left, as shown in the drawings, land 2Gb will close o the passage between ports 3,1115 and ,2817 and .hence stop any high pressure uid from ilowingto the chucking cylinder.

Low pressure huid, preferably at about p.s.i. is continuously flowing through line' 92 and line 96 to valve B. The low pressure fluid owing in the line does notV have sufficient pressure to operate the exhaust Valve 9 4 which is preferably set a few lp.s.i. higher than the pressure in the line, for example p.s.i. This low pressure is always present at Valve B, but is contained in chamber 11b by plug 33h in port 32b. Valve B is now in the position of FIGURE 3 and hence port 28h is in communication through chamber 11b with port 42h and the exhaust port 46h. The low pressure fluid will then o'w through valve B, and line 62 to chamber 76.

When valve B initially moves to the position of FIG- URE 3, the pressure in chamber 76`is at approximately 60' p.s.i. As this chamber is now connected to a line where the pressure is at approximately 15 p.s.i., the pressure in chamber 76 will reduce to approximately 15 p.s.i. or slightly above. The hydraulic fluid from chamber 76 will exhaust through exhaust regulator 914 which is set for a Vfew p.s.i. higher thanthe incoming line pressure of 15 p.s.i. Piston 68 will not move. However, the pressure in chamber 76 is reduced such that-the pressure exerted by the chuck on the workpiece is materally reduced.Y In other" words, when'valve B is moved to the position of FIGURE 3 the hydraulicuid in chamberV 76 is vented or exhausted through lines 62 and 96` and through the exhaustre'gulator 94 untilV the pressure isl at a level such that the exhaust regulator canclose. This pressure level will b e between 15 and 20 p.s.i.` When the operator wishes to completelyrelease the .work piece,l valve B is lmoved back'to the positionof FIGURE 1 and valve A is 'moved to theposition of FIGURE 3. `With the valves in this position, high pressure iluid williow int'ofvalve A through Vport Sila,

out port 32a, through iline S4, to'vport'SZ. As port'82 is o connected by passage 78 to left hand chamber 80, the high pressure lfluid will move piston 'tojth'e'right as shown in FIGURE 1 or to 'the release position. As the piston 'moves Vto the right theremaining pressure iluid 'in' the vchamber 76 will be exhausted through passage 7 4," line 62 to valve B. As valve B' is now in the position 'of FIGURES 1 and 2,'ports 28h and 3017 are connected together such that the exhausted pressure `tluid Ywill flow through line 60 to port 28a and thence through Vport 46a"to exhaust line 98. Y

In order to repeat the cycle theroperator need only move valve VA back to 'the' FIGURE 1 position. Y

The invention has been illustratedv as using manual i handles 24a and 24h for operating the'valve members A `and B. It should be understood however that these valves may be operated automatically in the same sequence as described. Furthermore, handles are not necessary for manual operation of the valves, asvother means may be used.

Whereas the preferred form of the invention h asvbeen shown and described herein, it should be realized that there are many modifications, substitutions and alterations thereto'within the scope of the following claims.

I claim:

1. A fluid control system f or use with a chucking cylnder or the like including a source of fluid pressure and a valving system connected thereto, saidvalving system including a first valve and a second valve, each having a reciprocal valve member movable between a rst and second station, each of said valves being connected to said source'of fluid pressure, 'a``rstuid conduit connected' to said first valve and a seconl fluid conduit connectedr to said second valve, said valve members being movable between a first position in-whichsaid rst iuid conduit is connected to exhaust and said second .lluidconduit is connected to the source of fluidpressure, fand-a second position in which the' pressure' supplied" to said second uid conduit is reduced from the pressure supplied when the valve members arein the'frstposi'tion,"s,aid valve members being movable `to` athird position inltwhich said first fluid conduit isA connected to said source of iluid pressure and said secondhuid conduit is connected to'exhaust.

2. The structure `of claim 1 further characterized ,byV a' low pressure regulator connected'be'twee' said sourceof uid pressurearid said second valve member;

` 3. The structure of claim 2 further characterizedby an exhaust regulator valve' connected between' said low pressure regulator andV said second valve, said exhaust regulator Valve being set at a pressure intermediate the source .pressure and the setting of saidlow' pressure regulator. v,

4. The structure of claim 1 further-characterized in that when said valve members arein said Afirst' position, said .second fluid condui'tcis 'connected through both of said valvesto said source of ilu'id pressureginfthe s'econd position said second "conduit is 'connected through one/of said valves to said source of fluid pressure, aridj'in" said 30 i including a rst valve and a'sec'ond rvvalve, each having "a reciprocal valve member movable'betweenj a trst and sec-` ond station, said first valve being connectedto said source of fluid pressure and a high pressure regulator connected between said source of 'fluid .pressureand .said Vvfirs'tvalve, said second valve beingc'onnec'ted 'tosaid' souic'e 'of'iluid pressure and a low pressure Yregulator connectedfbetween said second valve and said source ofuid'pres'sureg' an exhaust valve connected betweensaid low pressure regulator and said secoudvalve and being setat a: pressure intermediate the settings of said regulatorvalvesQa first fluid conduiticonnelc'ted .to'said ii'rlstvalvei'ad ahecoud liuid conduit connected tosaid second valve, and anexhaust connection from said first valve, said valves being effective to direct high pressure Huid to said second conduit when the valve members are inthe 'same position, said Ivalves being effective todirect high pressure fluid to said first conduit when said valve membersare' in opposite positions, said valves `being eiective to directV low pressure fluid to said second 'conduit' when said valve members are reversed 'from said second position.

Reresnces catas is the alepfthis patent UNTTED STATES PATENTS 2,051,052 Morgan Aug. 18, 1936 2,356,366 Wise Aug. 22, 19,44 2,566,811 StevensonV Sept. 4,- 1951 2,610,022 Meddock Sept. 9,' 1952 2,653,580 Moorel Sept. 29, 1953 FOREIGN PATENTS 736,614 France Sept. 20, 1932 630,721 Germany -June 8, 1936 

1. A FLUID CONTROL SYSTEM FOR USE WITH A CHUCKING CYLINDER OR THE LIKE INCLUDING A SOURCE OF FLUID PRESSURE AND A VALVING SYSTEM CONNECTED THERETO, SAID VALVING SYSTEM INCLUDING A FIRST VALVE AND A SECOND VALVE, EACH HAVING A RECIPROCAL VALVE MEMBER MOVABLE BETWEEN A FIRST AND SECOND STATION, EACH OF SAID VALVES BEING CONNECTED TO SAID SOURCE OF FLUID PRESSURE, A FIRST FLUID CONDUIT CONNECTED TO SAID FIRST VALVE AND A SECOND FLUID CONDUIT CONNECTED TO SAID SECOND VALVE, SAID VALVE MEMBERS BEING MOVABLE BETWEEN A FIRST POSITION IN WHICH SAID FIRST FLUID CONDUIT IS CONNECTED TO EXHAUST AND SAID SECOND FLUID CONDUIT IS CONNECTED TO THE SOURCE OF FLUID PRESSURE, AND A SECOND POSITION IN WHICH THE PRESSURE SUPPLIED TO SAID SECOND FLUID CONDUIT IS REDUCED FROM THE PRESSURE SUPPLIED WHEN THE VALVE MEMBERS ARE IN THE FIRST POSITION, SAID VALVE MEMBERS BEING MOVABLE TO A THIRD POSITION IN WHICH SAID FIRST FLUID CONDUIT IS CONNECTED TO SAID SOURCE OF FLUID PRESSURE AND SAID SECOND FLUID CONDUIT IS CONNECTED TO EXHAUST. 